It is interesting when I login to oracle in Linux and see this message on screen: “-bash: ulimit: open files: cannot modify limit: Operation not permitted“. It hit the maximum open files value in Unix/Linux user shell resource limitation. Then we run ulimit command to get the current maximum value and to increase it in the file /etc/security/limits.conf.
[oracle@dev01 ~]$ ulimit -Hn 65536 [oracle@dev01 ~]$ grep nofile /etc/security/limits.conf |grep hard oracle hard nofile 65536 # Let me purposely give a higher value ! [oracle@dev01 ~]$ ulimit -Hn 65537 -bash: ulimit: open files: cannot modify limit: Operation not permitted
ulimit [-SHacdefilmnpqrstuvx [limit]]
Provides control over the resources available to the shell and to processes started by it, on systems that allow such control. The -H and -S options specify that the hard or soft limit is set for the given resource. A hard limit cannot be increased once it is set; a soft limit may be increased up to the value of the hard limit. If neither -H nor -S is specified, both the soft and hard limits are set.